The present invention relates to ion exchange resins, and in particular, to ion exchange resins which are acidic in character.
Weak acid resins have been prepared by suspension polymerizing and crosslinking unsaturated carboxylic acids such as acrylic acid. Unfortunately, the polymerization of unsaturated carboxylic acids is highly exothermic making reaction control very difficult. Thus, the physical properties of the final resin product are typically very poor in quality.
Weak acid resins have been prepared by the post-hydrolysis of suspension polymerized, crosslinked acrylic acid esters. Unfortunately, such a process provides resin products which have undergone incomplete hydrolysis and exhibit poor physical strengths. Thus, such resins can have low exchange capacities and low resistance to osmotic shock.
In view of the deficiencies of the prior art, it would be highly desirable to provide a weak acid ion exchange resin with a high operating capacity which can be prepared in a controlled manner and exhibits high resistance to osmotic shock during regeneration.